Copper and zinc salts of dicyclohexyl phosphinic acid



United States Patent ABSTRACT OF THE DISCLOSURE This invention relatesto group consisting of the copper and zinc salts of dicyclo- Thisapplication is a division of application Ser. No. 357,738, filed Apr. 6,1964, and now Patent No. 3,293,208; and the latter is acontinuation-in-part of ap plication Ser. No. 292,721, and nowabandoned, filed July 3, 1963.

the polyolefins from the deteriorating and light, This difi'iculty ofrequiring one for over-all stabilization of polyolefins, while it is notintolerable, confers upon the user the inconvenience of having tomeasure, mix and add two materials instead of merely one.

Previous isolated attempts to uncover single stabilizers which couldferring both heat and light stability to polyolefin compositions.

throphosphimc acid. When these salts are added to polyolefins so thatthey are present in a concentration of about 0.01% to about 5.0% byweight of the composition, the resulting resin mixtures have highlyimproved stability to both light and heat as compared with a controlhaving no stabilizer. Moreover, the stabilizer is compatible withoutimparting substantial color ot the resin at proportions 3,409,654Patented Nov. 5, 1968 which are effective for the above-namedstabilization purposes.

It is surprising that the zinc and copper salts of this invention areeffective, since, in contrast thereto, related adequate stability, theprotective such conditions. It is highly unof this invention cannot beused in conjunction with other stabilizers. Other stabilizers may bedesirable When the phenols such as 2,6-di-tert-butyl-4-methylphenol,2,4,6-tritert-butyl phenol, 4,4'-thiobis G-tert-butyl-m-cresol 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis-6-tert-butyl-m-cresol) 4,4'-butylidenebis (6-tert-butyl-mcresol),2,6-bis(2-hydroxy-3-t-butyl 5 methylbenzyl)-pcresol,2,2'-methylenebis(4-ethyl-G-tert-butylphenol), 2,2-methylene-bis-(4,6-dinonylphenol) and 2,2'-methylenebis-(4-methyl-6-tert-butylphenol); phosphites such as triphenylphosphite,tridecylphosphite and dodecylphenylphosphite; and thiodipropionic acidesters such as dilauryl If desired, the resin composition may alsocontain coloring agents, extenders, plasticizers, solvents, etc.

The zinc and copper salts of this invention are conveniently prepared byreaction of dicyclohexylphosphine PH S NH4OH P R R S-NH4 The ammoniumsalt is then converted to the zinc or copper salt by reaction with awater-soluble zinc or copper salt, respectively.

The invention which follow.

is further illustrated by the examples Example l.Zincdicyclohexyldithiophosphinate A mixture of 86.5 g. sulfur, 500 ammoniumhydroxide,

then the mixture is heated cooled and filtered and to of ZnSO -7H O in250 cc.

tion without external heating; at C. for one hour. It is the filtrate isadded 178.6

.3,4.09,654. g. 4 I p ,l 5 a j: j .7 V I I 1 Example 2.-Copperdicyclohexyldithiophosphinate exposure in the Fade-Ometer and hoursexposure in a By following the procedure of Example 1, except for 14109oven to bntfle pomt HOURS EXPOSURE TO REACH BRITTLE POINT (INPOLYPROPYLENE) No. Dithiophosphinate Compound Percent Oven AgingFade-Ometer 140 0. Exposure Zinc dieyelohexyl. 0.05 260-280 0. 5 1, 0.01. 000 0.2 Y 200-216 400-500 0.2 240-200 800-900 0.25 1.300 0.2 125-135700-800 0.25 2 500 Manganese (II) dicycloh 0.25 300 500 Ammoniumdicyelohexyl 0.2 30-44 300-400 Ammonium di-n-butyL. 0. 2 8-20 100-200Zinc diphenyl 0.2 36-44 200-300 14 Dicyelohexyl acid 0.2 28-43 I 15Control 4-6 60-100 the substitution of copper sulfate for zinc sulfateused The following claims specify the extremely and untherein, thecopper dicyclohexyldithiophosphinate is obexpectedly active zinc andcopper dicyclohexyldithiophostained. phinates which materials are thepreferred members of the group. There are a number of other metal saltswhich Example Cir-Evaluation in polypropylene would perform to asignificantly lesser extent, but would nevertheless still operate asstabilizers within the over-all Efiediveness in P p py Was determined y2 concept of our invention. In this regard, it is noted that preparationof polypropylene compositions and exposure the lead dicyclohexyl,cadmium dicyclohexyl and manto ultraviolet light and heat, the time ofexposure before ganese dicyclohexyldithiophosphinates perform astabilizdevelopment of brittleness being determined. The proing functionwhile the ammonium and simple alkyl dicedure is described in more detailas follows. thiophosphinate compounds are not any better than thecontrols as shown in the table above. Procedure We, clakn;

1. A compound selected from the group consisting of Flfty grams of p ypp powder Were placed 111 the copper and zinc salts ofdicyclohexyldithiophosphinic a screw-top jar along with thepredetermined amount of i the compound to be tested. The blend wastumbled for Zinc dicyclohexyldithiophosphinate 2 hours. This mixture wasplaced on a 6- x 13 mill 3 Copper dicyclohexyldithiophosphinam whoserolls were heated to 360 F. and 320 F. respectively. This blend waspassed through the nip of the rolls, References Cited stripped from therolls and fed endwise into the nip to in- UNITED STATES PATENTS suremaximum mixing. This operation of stripping and 40 passing through thenip was repeated ten times. From the 3,004,996 10/1961 Arifkellafl260M299 sheet resulting from this blend, an l8-mill sheet was 3,168,4972/1965 Twltchett 260-4299 X compression-molded. From this molded sheet,specimens 3,233,248 3/1966 Rauhut 260-4299 X were cut out for theFade-Ometer test and the forceddfafl air oven test. TOBIAS E. LEVOW,Primary Examiner. In the following table of results are shown the hoursH. M. S. SNEED, Assistant Examiner.

